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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/networking/device_drivers/ethernet/google | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/networking/device_drivers/ethernet/google')
-rw-r--r-- | Documentation/networking/device_drivers/ethernet/google/gve.rst | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/Documentation/networking/device_drivers/ethernet/google/gve.rst b/Documentation/networking/device_drivers/ethernet/google/gve.rst new file mode 100644 index 000000000..6d73ee78f --- /dev/null +++ b/Documentation/networking/device_drivers/ethernet/google/gve.rst @@ -0,0 +1,166 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +============================================================== +Linux kernel driver for Compute Engine Virtual Ethernet (gve): +============================================================== + +Supported Hardware +=================== +The GVE driver binds to a single PCI device id used by the virtual +Ethernet device found in some Compute Engine VMs. + ++--------------+----------+---------+ +|Field | Value | Comments| ++==============+==========+=========+ +|Vendor ID | `0x1AE0` | Google | ++--------------+----------+---------+ +|Device ID | `0x0042` | | ++--------------+----------+---------+ +|Sub-vendor ID | `0x1AE0` | Google | ++--------------+----------+---------+ +|Sub-device ID | `0x0058` | | ++--------------+----------+---------+ +|Revision ID | `0x0` | | ++--------------+----------+---------+ +|Device Class | `0x200` | Ethernet| ++--------------+----------+---------+ + +PCI Bars +======== +The gVNIC PCI device exposes three 32-bit memory BARS: +- Bar0 - Device configuration and status registers. +- Bar1 - MSI-X vector table +- Bar2 - IRQ, RX and TX doorbells + +Device Interactions +=================== +The driver interacts with the device in the following ways: + - Registers + - A block of MMIO registers + - See gve_register.h for more detail + - Admin Queue + - See description below + - Reset + - At any time the device can be reset + - Interrupts + - See supported interrupts below + - Transmit and Receive Queues + - See description below + +Descriptor Formats +------------------ +GVE supports two descriptor formats: GQI and DQO. These two formats have +entirely different descriptors, which will be described below. + +Registers +--------- +All registers are MMIO. + +The registers are used for initializing and configuring the device as well as +querying device status in response to management interrupts. + +Endianness +---------- +- Admin Queue messages and registers are all Big Endian. +- GQI descriptors and datapath registers are Big Endian. +- DQO descriptors and datapath registers are Little Endian. + +Admin Queue (AQ) +---------------- +The Admin Queue is a PAGE_SIZE memory block, treated as an array of AQ +commands, used by the driver to issue commands to the device and set up +resources.The driver and the device maintain a count of how many commands +have been submitted and executed. To issue AQ commands, the driver must do +the following (with proper locking): + +1) Copy new commands into next available slots in the AQ array +2) Increment its counter by he number of new commands +3) Write the counter into the GVE_ADMIN_QUEUE_DOORBELL register +4) Poll the ADMIN_QUEUE_EVENT_COUNTER register until it equals + the value written to the doorbell, or until a timeout. + +The device will update the status field in each AQ command reported as +executed through the ADMIN_QUEUE_EVENT_COUNTER register. + +Device Resets +------------- +A device reset is triggered by writing 0x0 to the AQ PFN register. +This causes the device to release all resources allocated by the +driver, including the AQ itself. + +Interrupts +---------- +The following interrupts are supported by the driver: + +Management Interrupt +~~~~~~~~~~~~~~~~~~~~ +The management interrupt is used by the device to tell the driver to +look at the GVE_DEVICE_STATUS register. + +The handler for the management irq simply queues the service task in +the workqueue to check the register and acks the irq. + +Notification Block Interrupts +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The notification block interrupts are used to tell the driver to poll +the queues associated with that interrupt. + +The handler for these irqs schedule the napi for that block to run +and poll the queues. + +GQI Traffic Queues +------------------ +GQI queues are composed of a descriptor ring and a buffer and are assigned to a +notification block. + +The descriptor rings are power-of-two-sized ring buffers consisting of +fixed-size descriptors. They advance their head pointer using a __be32 +doorbell located in Bar2. The tail pointers are advanced by consuming +descriptors in-order and updating a __be32 counter. Both the doorbell +and the counter overflow to zero. + +Each queue's buffers must be registered in advance with the device as a +queue page list, and packet data can only be put in those pages. + +Transmit +~~~~~~~~ +gve maps the buffers for transmit rings into a FIFO and copies the packets +into the FIFO before sending them to the NIC. + +Receive +~~~~~~~ +The buffers for receive rings are put into a data ring that is the same +length as the descriptor ring and the head and tail pointers advance over +the rings together. + +DQO Traffic Queues +------------------ +- Every TX and RX queue is assigned a notification block. + +- TX and RX buffers queues, which send descriptors to the device, use MMIO + doorbells to notify the device of new descriptors. + +- RX and TX completion queues, which receive descriptors from the device, use a + "generation bit" to know when a descriptor was populated by the device. The + driver initializes all bits with the "current generation". The device will + populate received descriptors with the "next generation" which is inverted + from the current generation. When the ring wraps, the current/next generation + are swapped. + +- It's the driver's responsibility to ensure that the RX and TX completion + queues are not overrun. This can be accomplished by limiting the number of + descriptors posted to HW. + +- TX packets have a 16 bit completion_tag and RX buffers have a 16 bit + buffer_id. These will be returned on the TX completion and RX queues + respectively to let the driver know which packet/buffer was completed. + +Transmit +~~~~~~~~ +A packet's buffers are DMA mapped for the device to access before transmission. +After the packet was successfully transmitted, the buffers are unmapped. + +Receive +~~~~~~~ +The driver posts fixed sized buffers to HW on the RX buffer queue. The packet +received on the associated RX queue may span multiple descriptors. |